The performance of a concentrating photovoltaic module is related to the quality of cables used therein. The quality of a cable is related to both of cores and sheaths thereof. The refractoriness of and optical absorption by the sheaths are factors to be considered.
For converting sunlight into electricity, a concentrating photovoltaic module includes concentrating panels to concentrate the sunlight onto solar cells. Thus, there are spots of light. The spots of light are supposed to fall on the solar cells. Because of the failure or imprecision of a sunlight-tracing device, the spots of light might however fall on and burn parts of the concentrating photovoltaic module except the solar cells. Cables are most vulnerable among the parts.
In general, when encountering light, an object allows the light to penetrate, reflects the light or absorbs the light. By allowing the light to penetrate, the object lets optical energy go. By reflecting the light, the object bounces the optical energy off. By absorbing the light, the object absorbs the optical energy.
In the concentrating photovoltaic module, a cable includes at least two colored sheaths each for wrapping a core. When the concentrating photovoltaic module converts sunlight into electricity, the colored sheaths absorb more of the optical energy of the sunlight than sheaths of white or metallic colors. Should the spots of light fall on a cable, the sheaths would absorb and convert a large portion of the optical energy into heat that could burn the sheaths and cause short circuit between the cores or between the cores and metal parts, thus affecting the operation of the concentrating photovoltaic module.
As discussed above, the colors of the sheaths are too dark and the surfaces of the sheaths are too rough to dissipate heat after encountering the sunlight. The accumulation of heat in the sheaths cannot be avoided so that the burning of the sheaths cannot be prevented. Hence, the short circuit between the cores or between the cores and the other metal parts cannot be avoided. Hence, the normal operation of the concentrating photovoltaic module is not guaranteed.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.